Camera view not saved
Reading the other answer, it looks like you might have auto-key turned off, which would reset your camera to the original position. If you have auto-key ON, any change you make will be automatically recorded, even over old keys on the same frame. So it's not entirely necessary that you delete all the keys in order to reposition the camera; you just need to set a key on the frame you want to render (press "I" and select LocRotScale to key all transforms). 

This is just my opinion, but I generally work with auto-key turned on so I can avoid this. I'm also too lazy to want to set a key every time I make a change (I'm an animator; that's a lot of changes), so I let it do that for me. This is more of a workflow thing, but it is certainly something to know about. Good luck!

EDIT: Just remember that auto-key is not specific to cameras. It's a general automation tool that will capture attribute changes throughout the scene, such as a transformation or even a material change. You'll find the auto-key toggle button in the playhead in the timeline (the red circle).